The invention relates to the field of motor vehicles wherein the propulsion is provided by a heat engine and at least one electric machine.
When the vehicle slows down, its kinetic energy is normally lost.
It is for this reason that sometimes means are provided to recuperate this energy and store it for later use. This allows overall fuel consumption to be reduced.
Thus, such an electric machine is usually connected to a battery, intended to supply energy to this electric machine or to store energy from said machine.
Furthermore, it is known that a heat engine presents a poor efficiency at low power.
Consumption is therefore high at the idle point of a heat engine.
It is for this reason that, when a hybrid vehicle operates at idle point, the heat engine is normally shut down. The propulsion of the vehicle is provided by the electric machine, the battery thus being the only source of energy.
However, a battery has numerous drawbacks. It is expensive in relation to the overall cost of the vehicle and its life span is relatively short. Finally, it is heavy and cumbersome.
The purpose of the invention is to overcome the drawbacks associated with the use of a battery, while enabling the recuperation of the kinetic energy of the vehicle and avoiding the use of the heat engine at low power.